those are the mean ibd (identity by descent) rates for various populations in europe. the bigger the circle, the greater the number of ibd blocks larger than 1cM in length shared in common between each populations’ members. so, the larger the circles, the more segments of dna the individuals within those population share in common — i.e. the more alike they are genetically.
well, i never added the hajnal line to that map like i usually like to do for any map of europe that lands on my desktop (see here and here for examples). how remiss of me! (recall that populations within the hajnal line have had a historic tendency to marry late.)
i thought i’d better rectify this situation … so, here it is! mean ibd rates for europe PLUS the hajnal line. enjoy!:
update: see also jayman’s More on Farming and Inheritance Systems – Part I: IQ.
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